In recent years, a glass fiber-reinforced polyamide resin has been used as a metal substitute material for mechanism elements for automobiles, and the like, because of being excellent in strength, heat resistance, chemical resistance, specific gravity, and the like. In particular, engine peripheral members are demanded to have strength, vibration fatigue resistance, and the like under a high temperature environment, and therefore a reinforced polyamide resin composition is suitable therefor and various glass fiber-reinforced polyamide resin compositions are proposed (see, for example, Patent Literatures 1 and 2).
As the reduction in weight of automobile parts by the metal substitute material has been advanced, however, enhanced performance demands for such parts have been developed in recent years. Inter alia, in order to allow a glass fiber-reinforced polyamide resin to be applied to automotive structural members, long-term reliability has been demanded. In particular, in application to engine peripheral parts, enhancement in vibration fatigue resistance has been highly demanded.
In order to respond to such demands, for example, a glass fiber-reinforced polyamide resin composition containing an ethylene-based ionomer resin is proposed (see, for example, Patent Literature 3).
On the other hand, a technique of using a copolymer including a carboxylic anhydride-containing unsaturated vinyl monomer as an impact modifier is disclosed (see, for example, Patent Literature 4). In Patent Literature 4, a glass fiber-reinforced polyamide resin composition containing an ethylene/ethyl acrylate/maleic anhydride terpolymer is disclosed.
Furthermore, for the purpose of enhancement in the strength of a welded portion after welding, a glass fiber-reinforced polyamide resin composition containing polymaleic anhydride is disclosed (see, for example, Patent Literature 5).
In addition, for the purpose of enhancement in physical properties of recycled nylon, a polyamide resin composition including a polymer polymerized from maleic anhydride and an olefin is disclosed (see, for example, Patent Literature 6).